def test_move_player():
w = World()
w.add_player("nobus")
w.move_player("nobus", "left")
p = w.get_player("nobus")
d = p.get_direction()
assert d == "left"
def test_del_player():
n = "nobus"
w = World()
w.add_player(n)
w.del_player(n)
assert w.get_player(n) is None
def test_add_player():
n = "nobus"
w = World()
w.add_player(n)
assert w.get_player(n) is not None
